Legal change in 1999 enabled Post Office scandal, inquiry told

Introduced presumption computer-based evidence could not be wrong

John Bartlett, director of assurance and complex investigations at the Post Office, has told the Post Office IT Inquiry that changes to legal evidence introduced in 1999 effectively enabled the scandal to take place.

Under the Police and Criminal Evidence Act 1984, computer-based evidence could only be provided to courts alongside proof the system was working properly. However, following a review by the Law Commission, this requirement was dropped in favour of a presumption that a computer is working correctly, unless evidence can be provided to the contrary.

In the series of private prosecutions brought by the Post Office against subpostmasters accused of fraud, theft and false accounting, this tipped the balance strongly against the defendants, who lacked the knowledge or resources to challenge the unexplained losses on their accounts that the faulty IT system introduced. Many simply pleaded guilty to avoid a prison sentence.

The Post Office submitted the following to the Law Commission’s request for evidence, in support of the proposed change: “I consider that computer evidence is, in principal, no different from any other sort of evidence, and it should, in general terms, be admissible, so that any argument in court would be related to its weight rather than its admissibility.

“I therefore consider that there should be a presumption that the machine is in working order, etcetera, and if the defence wish to argue otherwise, then clearly, they should be able to do so. At present, I therefore consider the evidential requirements to be far too strict and can hamper prosecutions.”

The Horizon system worked as an EPOS for thousands of Post Office branches across the UK, as well as a backend finance system that tallied up accounts. It was developed by ICL – subsequently taken over by Fujitsu – and introduced in 1999. However, from the moment of its introduction the system introduced unexplained account imbalances that the Post Office automatically blamed on subpostmasters.

The legal change introduced in 1999 was compounded by the anachronistic power that the Post Office has to bring its own criminal prosecutions to court, a power that goes back to 1683, circumventing the usual checks and balances that prosecutions instigated by the police are typically subjected to by the Crown Prosecution Service.

The Post Office continued to prosecute sub-postmasters even after evidence was published in 2009 of serious issues with Horizon.

Indeed, as more evidence emerged over the next decade, the Post Office covered up the problems, and even assured Ed Davey, Post Office Minister between 2010 and 2012, that the system was working fine.

More than 700 sub-postmasters were prosecuted by the Post Office and convicted of fraud, theft or false accounting between 1999 and 2015. Many more were prosecuted but not convicted, and compelled to make up shortfalls with their own money.

At least four suicides have been linked with the scandal.

The Inquiry has found that senior executives at the Post Office were aware of the problems with the ICL/Fujitsu-developed system, but did nothing to prevent the prosecutions.

The convictions were only quashed following a group action against the Post Office led by former subpostmaster Alan Bates.